Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23.600
Filtrar
2.
Ecol Lett ; 23(3): 555-564, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31944513

RESUMO

Correlational ecological niche models have seen intensive use and exploration as a means of estimating the limits of actual and potential geographic distributions of species, yet their application to explaining geographic abundance patterns has been debated. We developed a detailed test of this latter possibility based on the North American Breeding Bird Survey. Correlations between abundances and niche-centroid distances were mostly negative, as per expectations of niche theory and the abundant niche-centre relationship. The negative relationships were not distributed randomly among species: terrestrial, non-migratory, small-bodied, small-niche-breadth and restricted-range species had the strongest negative associations. Distances to niche centroids as estimated from correlational analyses of presence-only data thus offer a unique means by which to infer geographic abundance patterns, which otherwise are enormously difficult to characterise.


Assuntos
Aves , Ecossistema , Animais , Densidade Demográfica
3.
Nat Commun ; 11(1): 536, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31988285

RESUMO

Climate change and increased variability and intensity of climate events, in combination with recovering protected species populations and highly capitalized fisheries, are posing new challenges for fisheries management. We examine socio-ecological features of the unprecedented 2014-2016 northeast Pacific marine heatwave to understand the potential causes for record numbers of whale entanglements in the central California Current crab fishery. We observed habitat compression of coastal upwelling, changes in availability of forage species (krill and anchovy), and shoreward distribution shift of foraging whales. We propose that these ecosystem changes, combined with recovering whale populations, contributed to the exacerbation of entanglements throughout the marine heatwave. In 2016, domoic acid contamination prompted an unprecedented delay in the opening of California's Dungeness crab fishery that inadvertently intensified the spatial overlap between whales and crab fishery gear. We present a retroactive assessment of entanglements to demonstrate that cooperation of fishers, resource managers, and scientists could mitigate future entanglement risk by developing climate-ready fisheries approaches, while supporting thriving fishing communities.


Assuntos
Comportamento Animal , Mudança Climática , Jubarte/fisiologia , Animais , Biodiversidade , Conservação dos Recursos Naturais , Ecossistema , Comportamento de Retorno ao Território Vital , Temperatura Alta , Jubarte/lesões , Densidade Demográfica
5.
Bull Entomol Res ; 110(1): 84-95, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31190643

RESUMO

Spodoptera exigua Hübner and Sesamia cretica Led. (Lep., Noctuidae) are two important pests of corn. In this study, the effect of weed bands in the corn field, as weedy culture, on population density and damages of the pests were evaluated during two growing seasons (2016/2017). Cumulative insect days (CID) of each lepidopteran pest in weedy culture were compared with non-weedy culture. Results showed that CIDs of S. exigua and S. cretica in the non-weedy corn culture were significantly higher than the weedy corn culture. There was no significant difference between the total yield in the weedy and non-weedy cultures. Also, determinations of spatial distributions of the pests in the weedy and no-weedy treatments using Taylor's power law (TPL) and Iwao's patchiness (IP) showed that TPL provides a better fit for the data than IP and spatial distributions of both pests on both cultures were aggregative. Moreover, minor differences were observed between spatial distribution parameters of the pests in the weedy and non-weedy cultures. Green's model was used for developing a fixed-precision sequential sampling plan of the pests on the weedy and no-weedy treatments. Optimum sample sizes of S. exigua ranged from 532 to 5370 and 428 to 5296 plants and S. cretica varied from 297 to 2040 and 43 to 186 plants in the non-weedy and weedy cultures based on the desired precision level (0.25-0.1). Estimated stop lines of non-weedy and weedy cultures for S. exigua ranged from 0.000057 to 52.59 and 0.00029 to 58.87 and for S. cretica ranged from 1.59 to 111.5 and 2.09 to 98.03 larval cumulative numbers, respectively (0.25-0.1). The performance of the sampling plan was validated by resampling analysis using RVSP software. Results of the study can be used in the integrated pest management program of corn fields.


Assuntos
Agricultura/métodos , Distribuição Animal , Spodoptera , Animais , Densidade Demográfica , Zea mays
6.
Phytopathology ; 110(1): 94-105, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31589103

RESUMO

Increasing evidence indicates that in wild ecosystems plant viruses are important ecological agents, and with potential to jump into crops, but only recently have the diversity and population dynamics of wild plant viruses begun to be explored. Theory proposes that biotic factors (e.g., ecosystem biodiversity, host abundance, and host density) and climatic conditions would determine the epidemiology and evolution of wild plant viruses. However, these predictions seldom have been empirically tested. For 3 years, we analyzed the prevalence and genetic diversity of Potyvirus species in preserved riparian forests of Spain. Results indicated that potyviruses were always present in riparian forests, with a novel generalist potyvirus species provisionally named Iberian hop mosaic virus (IbHMV), explaining the largest fraction of infected plants. Focusing on this potyvirus, we analyzed the biotic and climatic factors affecting virus infection risk and population genetic diversity in its native ecosystem. The main predictors of IbHMV infection risk were host relative abundance and species richness. Virus prevalence and host relative abundance were the major factors determining the genetic diversity and selection pressures in the virus population. These observations support theoretical predictions assigning these ecological factors a key role in parasite epidemiology and evolution. Finally, our phylogenetic analysis indicated that the viral population was genetically structured according to host and location of origin, as expected if speciation is largely sympatric. Thus, this work contributes to characterizing viral diversity and provides novel information on the determinants of plant virus epidemiology and evolution in wild ecosystems.


Assuntos
Ecossistema , Interações Hospedeiro-Patógeno , Doenças das Plantas , Vírus de Plantas , Plantas , Potyvirus , Especificidade de Hospedeiro , Interações Hospedeiro-Patógeno/fisiologia , Filogenia , Doenças das Plantas/virologia , Vírus de Plantas/classificação , Vírus de Plantas/fisiologia , Plantas/virologia , Densidade Demográfica , Potyvirus/classificação , Potyvirus/genética , Espanha
7.
Phytopathology ; 110(1): 130-145, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31573394

RESUMO

Epidemics of tomato yellow leaf curl virus (TYLCV; species Tomato yellow leaf curl begomovirus) have been problematic to tomato production in the southeastern United States since the first detection of the virus in Florida in the late 1990s. Current strategies for management focus on farm-centric tactics that have had limited success for controlling either TYLCV or its whitefly vector. Areawide pest management (AWPM)-loosely defined as a coordinated effort to implement management strategies on a regional scale-may be a viable management alternative. A prerequisite for development of an AWPM program is an understanding of the spatial and temporal dynamics of the target pathogen and pest populations. The objective of this study was to characterize populations of whitefly and TYLCV in commercial tomato production fields in southwestern Florida and utilize this information to develop predictors of whitefly density and TYLCV disease incidence as a function of environmental and geographical factors. Scouting reports were submitted by cooperating growers located across approximately 20,000 acres in southwestern Florida from 2006 to 2012. Daily weather data were obtained from several local weather stations. Moran's I was used to assess spatial relationships and polynomial distributed lag regression was used to determine the relationship between weather variables, whitefly, and TYLCV. Analyses showed that the incidence of TYLCV increased proportionally with mean whitefly density as the season progressed. Nearest-neighbor analyses showed a strong linear relationship between the logarithms of whitefly densities in neighboring fields. A similar relationship was found with TYLCV incidences. Correlograms based on Moran's I showed that these relationships extended beyond neighboring fields and out to approximately 2.5 km for TYLCV and up to 5 km for whitefly, and that values of I were generally higher during the latter half of the production season for TYLCV. Weather was better at predicting whitefly density than at predicting TYLCV incidence. Whitefly density was best predicted by the number of days with an average temperature between 16 and 24°C (T16to24), relative humidity (RH) over the previous 31 days, and vapor pressure deficit over the last 8 days. TYLCV incidence was best predicted by T16to24, RH, and maximum wind speed over the previous 31 days. Results of this study helped to identify the extent to which populations of whitefly and TYLCV exist over the agricultural landscape of southwestern Florida, and the environmental conditions that favor epidemic growth. This information was used to propose an approach to AWPM for timing control measures for managing TYLCV epidemics.


Assuntos
Begomovirus , Hemípteros , Lycopersicon esculentum , Doenças das Plantas , Animais , Begomovirus/fisiologia , Florida , Hemípteros/virologia , Lycopersicon esculentum/virologia , Doenças das Plantas/virologia , Densidade Demográfica , Sudeste dos Estados Unidos , Fatores de Tempo
8.
Integr Zool ; 15(1): 79-86, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31305022

RESUMO

Following significant developments in technology, alternative devices have been applied in fieldwork for animal and plant surveys. Thermal-image acquisition cameras installed on unmanned aerial vehicles (UAVs) have been used in animal surveys in the wilderness. This article demonstrates an example of how UAVs can be used in high mountainous regions, presenting a case study on the Sichuan snub-nosed monkey with a detection rate of 65.19% for positive individual identification. It also presents a model that can prospectively predict population size for a given animal species, which is based on combined initial work using UAVs and traditional surveys on the ground. A great potential advantage of UAVs is significantly shortening survey procedures, particularly for areas with high mountains and plateaus, such as the Himalayas, the Qinghai-Tibet Plateau, Hengduan Mountains, the Yunnan-Gui Plateau and Qinling Mountains in China, where carrying out a traditional survey is extremely difficult, so that species and population surveys, particularly for critically endangered animals, are largely absent. This lack of data has impacted the management of endangered animals as well as the formulation and amendment of conservation strategies.


Assuntos
Distribuição Animal , Colobinae/fisiologia , Tecnologia de Sensoriamento Remoto/métodos , Aeronaves , Animais , China , Conservação dos Recursos Naturais , Ecossistema , Densidade Demográfica , Tecnologia de Sensoriamento Remoto/instrumentação
9.
Ambio ; 49(1): 107-117, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30852778

RESUMO

Stock enhancement activities provide an opportunity to examine density-dependent suppression of population biomass which is a fundamental issue for resource management and design of no-take-zones. We document 'catch-and-wait' fisheries enhancement where all but the largest lobsters are thrown back, recapturing them later after they have grown to a larger size. The residency, rate of return, and potential negative density-dependent effects of this activity are described using a combination of tagging and v-notching and by relating spatial growth patterns to population density defined with Catch Per Unit Effort. The results successfully demonstrated the concept of catch-and-wait practices. However, a density-dependent suppression of growth (in body size) was observed in male lobsters. This demonstrates a mechanism to explain differences in lobster sizes previously observed across EU fishing grounds with different stock densities. This negative effect of density could also affect individual biomass production in marine reserve or no-take zones.


Assuntos
Conservação dos Recursos Naturais , Pesqueiros , Biomassa , Peixes , Masculino , Densidade Demográfica
10.
Accid Anal Prev ; 134: 105244, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31405515

RESUMO

This paper reviews the literature on the relationship between the built environment and roadway safety, with a focus on studies that analyse small geographical units, such as census tracts or travel analysis zones. We review different types of built environment measures to analyse if there are consistent relationships between such measures and crash frequency, finding that for many built environment variables there are mixed or contradictory correlations. We turn to the treatment of exposure, because built environment measures are often used, either explicitly or implicitly, as measures of exposure. We find that because exposure is often not adequately controlled for, correlations between built environment features and crash rates could be due to either higher levels of exposure or higher rates of crash risk per unit of exposure. Then, we identify various built environment variables as either more related to exposure, more related to risk, or ambiguous, and recommend further targeted research on those variables whose relationship is currently ambiguous.


Assuntos
Acidentes de Trânsito , Ambiente Construído , Humanos , Densidade Demográfica , Medição de Risco , Segurança , Análise Espacial
11.
BMC Public Health ; 19(1): 1426, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666049

RESUMO

BACKGROUND: A rapidly growing body of research suggests that qualities of the built environment can promote active living among children and youth. Nevertheless, shortcomings in the current evidence for understanding which built environment characteristics provide opportunities for taking part in activities in childhood remain. This study aimed to examine whether population density, green spaces, and facilities/amenities are associated with participation in leisure-time physical activity (PA), organized activities, and social activities with friends and peers in Norwegian 8-year-olds. METHODS: Data from a sample of 23,043 children from the Norwegian Mother and Child Cohort Study (MoBa) were linked with geospatial data about the built environment. The questionnaire data reported by mothers provided information on the children's leisure activities. We computed exposure to neighborhood population density and access to green spaces and facilities/amenities within 800- and 5000-m radii of the participants' home addresses using geographic information systems. Associations were estimated using logistic regression models. RESULTS: We found beneficial associations between having a park within 800-m and more leisure-time PA during the summer. Furthermore, children living in neighborhoods with higher proportions of green space participated in more PA during the winter. More densely populated areas and access to facilities were associated with participation in organized and social activities. Specifically, we observed that more playgrounds/sport fields in the neighborhood were the strongest and most consistent correlate of activity participation in Norwegian 8-year-olds by being related to more socialization with friends and peers. CONCLUSION: This population-based study underscores the importance of access to a variety of venues and opportunities for different activities in the immediate neighborhood surroundings and in the greater community to support participation in physical activity and organized and social activities in childhood.


Assuntos
Comportamento Infantil , Planejamento Ambiental , Exercício , Parques Recreativos , Densidade Demográfica , Características de Residência , Esportes , Adulto , Criança , Estudos de Coortes , Estudos Transversais , Planejamento Ambiental/estatística & dados numéricos , Feminino , Sistemas de Informação Geográfica , Humanos , Atividades de Lazer , Modelos Logísticos , Masculino , Mães , Noruega , Jogos e Brinquedos , Características de Residência/estatística & dados numéricos , Inquéritos e Questionários
12.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(5): 463-467, 2019 Sep 27.
Artigo em Chinês | MEDLINE | ID: mdl-31713372

RESUMO

OBJECTIVE: To understand the situation of Schistosoma japonicum infections in wild animals in transmission-controlled schistosomiasis-endemic areas in Jiangxi Province, so as to provide scientific evidence for implementing precision control interventions and achieving the goal of transmission interruption and elimination of schistosomiasis. METHODS: Five endemic villages from Ruichang City and Pengze County that were heavily endemic for schistosomiasis in Jiangxi Province, were selected as the study villages. Wild animals like wild mice were captured, and the livers of wild animals were purchased from the snail habitats in the study villages for detection of S. japonicum infections. In the study villages, S. japonicum human infections were screened using indirect hemagglutination assay (IHA) followed by parasitological examinations with miracidial hatching test and Kato-Katz method, and the S. japonicum infection in livestock was tested using a miracidial hatching test with a plastic tube. In addition, snail survey was conducted in the study villages by means of systematic sampling combined with environmental sampling, and the S. japonicum infection in snails was detected using a loop-mediated isothermal amplification (LAMP) assay. RESULTS: A total of 240 liver specimens were sampled or purchased from 5 species of wild animals in the study villages, including wild mice, weasels, pigs, deer and rabbits. A total of 172 wild mice were captured, with a 2.91% rate of S. japonicum infection, and there was no S. japonicum infection detected in other wild animals. The prevalence of Capillaria hepatica infection was 12.21%, 1.96% and 12.50% in wild mice, deer and pigs, respectively. In addition, there was no S. japonicum infection found in either humans or livestock in the study villages, and the mean snail density varied from 0.13 to 0.80 snails/0.1 m2 in the study villages. LAMP assay detected S. japonicum infection in 2 tubes in a study village. CONCLUSIONS: The role of wild animals in schistosomiasis transmission and their potential risks can not be neglected in hilly schistosomiasis-endemic areas of Jiangsu Province after transmission control. Intensified surveillance and targeted control measures should be implemented to consolidate schistosomiasis control achievements.


Assuntos
Animais Selvagens , Schistosoma japonicum , Esquistossomose Japônica , Animais , Animais Selvagens/parasitologia , China/epidemiologia , Humanos , Fígado/parasitologia , Camundongos , Densidade Demográfica , Prevalência , Coelhos , Esquistossomose Japônica/epidemiologia , Esquistossomose Japônica/prevenção & controle , Caramujos/fisiologia , Inquéritos e Questionários , Suínos
13.
Zootaxa ; 4576(3): zootaxa.4576.3.7, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-31715752

RESUMO

Culiseta ochroptera is a rare mosquito species in Germany, for which little ecological data are available. It is a species of peatlands where it occurs in a variety of habitats in different mire types. These landscape elements, strongly reduced and degraded by human use, are now often protected areas. Within the scope of a Germany-wide mosquito monitoring program, Cs. ochroptera was documented several times from 2011 to 2017, complementing historical data about its distribution and ecology. The records in northern and eastern Germany represent different types of peatlands and aquatic sites. Highest seasonal population densities were recorded in July and August, caused by the second of at least two annual generations. The morphological variants of Cs. ochroptera as described in the past were assigned to three forms (light, normal, dark), and the previously noted but neglected presence of postspiracular scales is recognized as a useful character supporting species identification.


Assuntos
Culicidae , Animais , Ecologia , Ecossistema , Alemanha , Humanos , Densidade Demográfica
14.
Rev Soc Bras Med Trop ; 52: e20190278, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31778421

RESUMO

INTRODUCTION: Trypanosoma cruzi is the etiological agent of Chagas disease (CD), a zoonotic infection transmitted by triatomine bug vectors to human beings. Although the story of this parasitic infection was born in Brazil and here this has made major step forward information, the same cannot be said about the actual distribution of the triatomine vector in several areas of this country. The aim of this study was to assess the occurrence of triatomine species in an endemic region for CD in Northeastern Brazil. METHODS: A retrospective study was performed using data obtained from 2008 to 2017. All information was provided by the V Gerência Regional de Saúde of the state of Pernambuco. The spatial distribution of triatomine species was analyzed by drawing a map using the Quantum geographic information system. RESULTS: A total of 4,694 triatomine specimens (469.4 ± 221.2 per year) were collected during the period 2008-2017, with 94.5% (4,434/4,694) at the intradomicile and 5.5% (260/4,694) at peridomicile environment. Of all arthropods collected, 92.5% (4,340/4,694) and 7.5% (354/4,694) were adults and nymphs, respectively. The species most frequently detected were Panstrongylus lutzi (30.36%), Triatoma brasiliensis (26.12%), Triatoma pseudomaculata (22.43%), and Panstrongylus megistus (20.54%). CONCLUSIONS: These data contribute to a better understanding of the distribution of T. cruzi infection in the Northeastern region of Brazil. Preventive measures based on vector control should be implemented in the study area in order to reduce the burden this neglected tropical disease.


Assuntos
Distribuição Animal , Insetos Vetores/classificação , Triatominae/classificação , Animais , Brasil , Doença de Chagas/transmissão , Doenças Endêmicas , Densidade Demográfica , Estudos Retrospectivos
15.
Environ Monit Assess ; 191(12): 739, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31709453

RESUMO

The provision capacity of ecosystem services is affected by land-use/land-cover (LULC) change and biophysical and socio-economic characteristics. Studies related to ecosystem service values (ESVs) and their impact factors can provide a good reference for natural capital management. In this paper, the temporal and spatial dynamics of LULC and ESVs in the Nansihu Lake basin, China, since the reform and opening of China were analyzed by a combined method of spatial analysis and correlation analysis, and the factors that influence ESV changes were discussed. The results indicated that the main LULC changes were the enormous loss of cultivated land and rapid urban land expansion since the policy of reformation and opening in 1978. The ESVs in the basin decreased by 1.64% (1.70 × 108 US$) from 1975 to 2015, and the main impact factors of this temporal change in ESVs were the changes in waterbodies and cultivated land. Spatial patterns of ESVs were significantly influenced by socio-economic factors in the basin, such as population density and intensity of land use. This research provides alternatives and robust information for policy-making processes for the Nansihu Lake basin, and similar work can be conducted in other parts of the country.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Monitoramento Ambiental , Agricultura , China , Lagos , Densidade Demográfica , Análise Espacial , Urbanização
16.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(4): 410-413, 2019 Jul 29.
Artigo em Chinês | MEDLINE | ID: mdl-31612677

RESUMO

OBJECTIVE: To analyze the endemic sitaution of schistosomiasis based on geographic information system (GIS) in Wuhan City in 2017, so as to provide the reference for further schistosomiasis control activities. METHODS: According to the data of the annual report on the prevention and control of schistosomiasis in Wuhan City in 2017, the spatial database regarding the endemic situation of schistosomiasis was established and analyzed by ArcMap 10.2. RESULTS: The 593 schistosomiasis-endemic villages in Wuhan City were mainly located in the Yangtze River and its major tributaries. Kernel density analysis showed that the endemic villages of three regions with the highest density was located in the west of Caidian District (Zhuru Street), the east of Hannan District (Shamao Street) and the southwest corner of Xinzhou District (Yangluo Street). The sero-positive population was densely distributed in the West of Caidian District (Zhuru Street), which accounted for 34.23% of all seruo-positives in the city. There were 492 farming cattle fenced in Donggan Village in Hongbei Street of Caidian District. A higher density of the area with Oncomelania hupensis snails was located in the southwest region of Caidian District (Xiaosi Street), accounting for 31.22% of the total area with snails. In 2017, the re-emerging area with snails was 36.60 hm2. The high kernel density region with snails was located in Zhuru Street of Caidian District. The region with high density of living snails was located in the central region of Hannan District (Hongbei Production Brigade), the average density of living snails was 0.36 snails/0.1 m2. CONCLUSIONS: The endemic situation of schistosomiasis is at a low level in Wuhan City, and the spatial distribution is not uniform. In some local areas, the historical endemic situation of schistosomiasis is serious and the high risk factors are more concentrated. It is necessary to strengthen the surveillance of schistosomiasis.


Assuntos
Sistemas de Informação Geográfica , Esquistossomose , Animais , Anticorpos Anti-Helmínticos/sangue , China/epidemiologia , Doenças Endêmicas/estatística & dados numéricos , Humanos , Densidade Demográfica , Vigilância da População , Fatores de Risco , Esquistossomose/sangue , Esquistossomose/epidemiologia , Caramujos
17.
Plant Dis ; 103(12): 3093-3100, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31613191

RESUMO

In Nebraska, rotation of soybean (Glycine max) fields to corn (Zea mays) is a major practice to manage the soybean cyst nematode (SCN; Heterodera glycines). However, factors associated with SCN population density decline during corn rotation are not clearly defined. This study addresses that question using a modeling approach. Seventy-nine fields were sampled in 2009, 2010, and 2011 to determine SCN population densities (eggs/100 cm3 of soil) before and after rotation. After rigorous field screening and model testing and validation, the regression model Log(Pf)^=-2.3360+0.8368LogPi+0.4333pH was developed, where Log Pf is the natural log of SCN eggs at the end of the rotation year, Pi is the population density before rotation, and pH is the soil pH. Model goodness-of-fit was assessed through residual analysis, information criteria, and other remedial measures. Model overdispersion was 1.04. Validation in a 50 and a 75% random sample from the original data set showed little change in model regression coefficients, standard errors, and associated significance, confirming model fit and performance. The model indicates that for one-unit increase in soil pH, SCN Pf is expected to increase by 53.7% at constant Pi, and correspondingly, a 10% change in Pi will result in about 8.3% change in Pf at constant soil pH. The model suggested that SCN population levels before corn rotation and soil pH are major determinants of observed SCN population density reduction after annual corn rotation in Nebraska. This model has potential for use in SCN risk analysis and in predicting SCN population decline after corn rotation in the state.


Assuntos
Agricultura , Nematoides , Solo , Zea mays , Agricultura/métodos , Animais , Nebraska , Nematoides/fisiologia , Doenças das Plantas/parasitologia , Doenças das Plantas/prevenção & controle , Densidade Demográfica , Análise de Regressão , Rotação , Solo/parasitologia , Zea mays/crescimento & desenvolvimento , Zea mays/parasitologia
18.
BMC Bioinformatics ; 20(1): 526, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31660852

RESUMO

BACKGROUND: Our current understanding of archaic admixture in humans relies on statistical methods with large biases, whose magnitudes depend on the sizes and separation times of ancestral populations. To avoid these biases, it is necessary to estimate these parameters simultaneously with those describing admixture. Genetic estimates of population histories also confront problems of statistical identifiability: different models or different combinations of parameter values may fit the data equally well. To deal with this problem, we need methods of model selection and model averaging, which are lacking from most existing software. RESULTS: The Legofit software package allows simultaneous estimation of parameters describing admixture, and the sizes and separation times of ancestral populations. It includes facilities for data manipulation, estimation, analysis of residuals, model selection, and model averaging. CONCLUSIONS: Legofit uses genetic data to study the history of a subdivided population. It is unaffected by recent history and can therefore focus on the deep history of population size, subdivision, and admixture. It outperforms several statistical methods that have been widely used to study population history and should be useful in any species for which DNA sequence data is available from several populations.


Assuntos
Modelos Genéticos , Biometria , Humanos , Densidade Demográfica , Software
19.
BMC Public Health ; 19(1): 1279, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31590643

RESUMO

BACKGROUND: Studies from Western countries reported a positive relationship between residential density (RD) and physical activity (PA) among adults. There was no such study from China, a rapidly-urbanizing country in the world. This study aimed to investigate the RD-PA association among urban adults in China. METHODS: A multistage sampling approach was used to randomly select participants (aged 35-74 years old) in urban areas of Nanjing in 2017. The outcome variable was PA (dichotomized into "sufficient" or "insufficient"), while the independent variable was RD (tertiled into three sub-groups). Odds ratios (OR) and 95% confidence interval (CI) were computed to examine the RD-PA association using mixed-effects logistic regression models with adjustment for age, sex, nationality, marriage, educational attainment, employment status, body weight status, green space and neighborhood-level clustering effects. RESULTS: Of the 1568 eligible participants, 1551 were interviewed (response rate = 98.9%), with the mean age (standard deviation) of 54.7 (11.1) years old, and 46% of men. After adjustment for potential confounders and community-level clustering effects, participants lived in communities with higher (OR = 0.31, 95% CI = 0.21, 0.47) and middle (OR = 0.70, 95% CI = 0.50, 0.99) residential density were significantly less likely to achieve sufficient physical activity relative to their counterparts lived in the lower densed communities. Similar negative RD-PA association was examined for men or women, separately. The difference in the ORs between the middle and higher RD tertiles was also statistically significant (P < 0.01). CONCLUSIONS: A negatively gradient RD-PA association, independent of body weight status and green space, was observed among urban adults in regional China. It has public health implications for China to help residents' promote and maintain physical activity through planning and constructing PA-/health-friendly built environment in future.


Assuntos
Exercício , Densidade Demográfica , Características de Residência/estatística & dados numéricos , População Urbana/estatística & dados numéricos , Adulto , Idoso , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
20.
Rev Saude Publica ; 53: 84, 2019.
Artigo em Inglês, Português | MEDLINE | ID: mdl-31576944

RESUMO

OBJECTIVE: To describe the infestation of the municipalities of São Paulo by the vectors Aedes aegypti and Aedes albopictus, characterize seasonality and analyze average temperatures and larval densities. METHODS: We used maps with information on the infestation of municipalities between 1986 and 2015. The analysis of larval density of the species by the Wilcoxon test used the Breteau index values for Ae. aegypti and Ae. albopictus obtained from the Superintendency for Endemic Diseases Control database. In the seasonal description, arithmetic means of each vector were calculated by month and year. Mean temperature analyses were presented on maps with color gradients. RESULTS: The state of São Paulo is currently almost totally infested, with co-occurrence of species in 93.64% of the municipalities. The seasonality analysis showed the first quarter as the most favorable period for larval abundance. The increase of mean temperatures in geographical areas coincided with the temporal trajectory of Ae. aegypti territorial expansion. The mean larval density found was higher for Ae. aegypti than for Ae. albopictus (p = 0.00). CONCLUSIONS: Initially, these Culicidae occupied distinct and opposing areas. Over time, however, co-occurrence showed how great their capacity for adaptation is, even in the face of different social and urban conjunctures. The increase of the mean temperature contributed to Ae. Aegypti 's geographic expansion, as well as to the clearly seasonal profile of both species. In general, larval infestation by Ae. aegypti prevailed, which evidenced its competitive superiority. These data provide a better understanding of the dynamics of arboviral transmission in the state of São Paulo and can be used in vector surveillance and control.


Assuntos
Aedes , Arbovirus , Mosquitos Vetores , Animais , Brasil/epidemiologia , Cidades/epidemiologia , Densidade Demográfica , Estudos Retrospectivos , Estações do Ano , Análise Espaço-Temporal , Temperatura Ambiente , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA